At the slowest speed my wing will foil (7-10mph) I get plenty of water flow without a pump. I initially thought I needed a pump too. Nope. There is a reason Lift does not use a water pump.
Just sharing my experience. I think keeping the design as simple as possible is the key to success. I mean, we are already trying to cram 40 lbs of crap into a tiny enclosure. 
